The HOCl dry fog-is it safe for human cells?

This study aims to investigate if high-concentration HOCl fogging disinfection causes cytotoxicity and genotoxicity to cultured primary human skin fibroblasts. The cells were exposed to a dry fog of HOCl produced from solutions with a concentration of 300 ppm (5.72 mM) or 500 ppm (9.53 mM). After four times when fibroblasts were exposed to aerosolized HOCl at a concentration of 500 ppm for 9 minutes, significant cytotoxicity and genotoxicity effects were observed. Significant changes in the morphology of fibroblasts and cell death due to membrane disruption were observed, independent of the number of exposures. Flow cytometry analyses performed under these experimental conditions indicated a decrease in the number of cells with an intact cell membrane in the exposed samples compared to the sham samples, dropping to 49.1% of the total cells. Additionally, under the same conditions, the neutral comet assay results demonstrated significant DNA damage in the exposed cells. However, no analogous damages were found when the cells were exposed to aerosolized HOCl generated from a 300-ppm solution for 3 minutes, whether once or four times. Therefore, we have concluded that aerosolized HOCl in dry fog, with a concentration exceeding 300 ppm, can cause cytotoxic and genotoxic effects on human skin fibroblasts.

New approaches for low phototoxicity imaging of living cells and tissues.

Fluorescence microscopy is a powerful tool used in scientific and medical research, but it is inextricably linked to phototoxicity. Neglecting phototoxicity can lead to erroneous or inconclusive results. Recently, several reports have addressed this issue, but it is still underestimated by many researchers, even though it can lead to cell death. Phototoxicity can be reduced by appropriate microscopic techniques and carefully designed experiments. This review focuses on recent strategies to reduce phototoxicity in microscopic imaging of living cells and tissues. We describe digital image processing and new hardware solutions. We point out new modifications of microscopy methods and hope that this review will interest microscopy hardware engineers. Our aim is to underscore the challenges and potential solutions integral to the design of microscopy systems. Simultaneously, we intend to engage biologists, offering insight into the latest technological advancements in imaging that can enhance their understanding and practice.

Adhesion and morphology of mammalian cells on nanoporous and nonporous spherical carbon substrates.

Three spherical activated carbons (SACs) were used as substrates for mammalian cell proliferation. SACs were obtained by carbonizing styrene-co-divinylbenzene ion exchangers 35WET, XAD4, or 1200H. The new materials (XAD_C, WET_C, and H_C) were characterized by adsorption-desorption nitrogen isotherms and mercury intrusion porosimetry. XAD_C and WET_C exhibited well-developed BET surface areas, similar total pore volumes, and highly different pore size distributions. H_C was nonporous spherical material-reference material. The XAD_C was meso-macroporous, but the WET_C was micro-mesoporous. All SACs were not cytotoxic toward Leydig TM3 cells. The differences in porous structure and morphology of the carbon scaffolds led to morphological differences in adhered cells. The monolayer of cells was distributed flat over the entire WET_C and H_C surfaces. Leydig TM3 cells adhered to nonporous SAC but were easily washed out due to weak adhesion. The cells adhered in clusters to XAD_C and proliferated in clusters. As microscopic techniques and viability tests demonstrated, only nanoporous carbons provided a good surface for the attachment and proliferation of eukaryotic cells.

Preliminary Study on the Effect of a Single High-Energy Electromagnetic Pulse on Morphology and Free Radical Generation in Human Mesenchymal Stem Cells.

The effect of nanosecond electromagnetic pulses on human health, and especially on forming free radicals in human cells, is the subject of continuous research and ongoing discussion. This work presents a preliminary study on the effect of a single high-energy electromagnetic pulse on morphology, viability, and free radical generation in human mesenchymal stem cells (hMSC). The cells were exposed to a single electromagnetic pulse with an electric field magnitude of ~1 MV/m and a pulse duration of ~120 ns generated from a 600 kV Marx generator. The cell viability and morphology at 2 h and 24 h after exposure were examined using confocal fluorescent microscopy and scanning electron microscopy (SEM), respectively. The number of free radicals was investigated with electron paramagnetic resonance (EPR). The microscopic observations and EPR measurements showed that the exposure to the high-energy electromagnetic pulse influenced neither the number of free radicals generated nor the morphology of hMSC in vitro compared to control samples.

Recognition and Processing of Visual Information after Neuronavigated Transcranial Magnetic Stimulation Session.

BACKGROUND: Transcranial magnetic stimulation (TMS) is a method of noninvasive and painless stimulation of the nervous system, which is based on Faraday's law of electromagnetic induction. Over the past twenty years, the TMS technique has been deployed as a tool for the diagnosis and therapy of neurodegenerative diseases, as well as in the treatment of mental disorders (e.g., depression). METHODS: We tested the inhibitory effects of repetitive TMS (rTMS) on reaction times to militarily relevant visual stimuli amidst distractors and on accompanying blood oxygenation level dependent (BOLD) signal functional magnetic resonance imaging (fMRI) in 20 healthy people. rTMS was applied over the visual cortices, V1, on both hemispheres with the inhibitory theta burst paradigm with the intensity of 70% of the active motor threshold fMRI in 20 healthy people. RESULTS: Analysis of the reaction time to visual stimuli after using TMS to the V1 visual cortex revealed an increase in the number of incorrect recognitions, and the reaction time was from 843 to 910 ms. In the subgroup of participants (n = 15), after the stimulation, there were significant reductions of BOLD signal in blood flow within V1 cortices. CONCLUSIONS: The studies of reaction times after the rTMS revealed the inhibitory effect of rTMS on the reaction times and recognition performance of significant (military) objects in the visual field.

Studies on the Effect of Graphene Oxide Deposited on Gold and Nickel Microsieves on Prostate Cancer Cells DU 145.

This work shows the effect of graphene oxide deposition on microsieves' surfaces of gold and nickel foils, on DU 145 tumor cells of the prostate gland. The sieves were made by a laser ablation process. The graphene oxide (GO) deposition process was characterized by the complete covering of the inner edges of the microholes and the flat surface between the holes with GO. Electron microscanning studies have shown that due to the deposition method applied, graphene oxide flakes line the interior of the microholes, reducing the unevenness of the downstream surfaces during the laser ablation process. The presence of graphene oxide was confirmed by Fourier infrared spectroscopy. During the screening (sieving) process, the microsieves were placed in a sieve column. Gold foil is proven to be a very good material for the screening of cancer cells, but even more so after screening as a substrate for re-culture of the DU 145. This allows a potential recovery of the cells and the development of a targeted therapy. The sieved cells were successfully grown on the microsieves used in the experiment. Graphene oxide remaining on the surface of the nickel sieve has been observed to increase the sieving effect. Although graphene oxide improved separation efficiency by 9.7%, the nickel substrate is not suitable for re-culturing of the Du 145 cells and the development of a targeted therapy compared to the gold one.

Impact of one HF-rTMS session over the DLPFC and motor cortex on acute hormone dynamics and emotional state in healthy adults: a sham-controlled pilot study.

Studies indicate that high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) can lower cortisol concentration or output, with some evidence suggesting a link to testosterone. Together, these stress and social hormones might help regulate the emotional response to HF-rTMS. This pilot study evaluated the effect of HF-rTMS on acute testosterone and cortisol dynamics and emotional state in eleven healthy adults. Using a sham-controlled, single-blind, crossover design, participants completed a HF-rTMS session targeting the dorsolateral prefrontal cortex (DLPFC) and motor cortex on separate days. Stimulation (250 total pulses) was applied at 90% of the resting motor threshold. Salivary testosterone and cortisol, mood, motivation, anxiety, and heart rate (HR) were assessed before (T1) and 1 (T2), 15 (T3), and 30 min (T4) after each session. There were no significant session differences in testosterone and cortisol concentration, mood, motivation, and HR. Although DLPFC stimulation produced less anxiety (vs. motor cortex), and testosterone output was stable across both treatments (vs. sham-related decline in testosterone), neither differed from the sham. Within-person fluctuations in testosterone, mood, motivation, and/or anxiety were significantly related across the DLPFC and motor cortex trials only. In conclusion, a single sub-maximal session of HF-rTMS did not affect the hormonal, emotional, or physiological state of healthy adults, relative to a sham. However, the emergence of stimulation-specific testosterone and/or emotional linkages suggests that the repeated effects of HF-rTMS may also manifest at the individual level. This offers another pathway to explain the therapeutic efficacy of rTMS and a model to explore interindividual variability in health-related outcomes.

Nanosecond Pulsed Electric Field Only Transiently Affects the Cellular and Molecular Processes of Leydig Cells.

The purpose of this study was to verify whether the nanosecond pulsed electric field, not eliciting thermal effects, permanently changes the molecular processes and gene expression of Leydig TM3 cells. The cells were exposed to a moderate electric field (80 quasi-rectangular shape pulses, 60 ns pulse width, and an electric field of 14 kV/cm). The putative disturbances were recorded over 24 h. After exposure to the nanosecond pulsed electric field, a 19% increase in cell diameter, a loss of microvilli, and a 70% reduction in cell adhesion were observed. Some cells showed the nonapoptotic externalization of phosphatidylserine through the pores in the plasma membrane. The cell proportion in the subG1 phase increased by 8% at the expense of the S and G2/M phases, and the DNA was fragmented in a small proportion of the cells. The membrane mitochondrial potential and superoxide content decreased by 37% and 23%, respectively. Microarray's transcriptome analysis demonstrated a negative transient effect on the expression of genes involved in oxidative phosphorylation, DNA repair, cell proliferation, and the overexpression of plasma membrane proteins. We conclude that nanosecond pulsed electric field affected the physiology and gene expression of TM3 cells transiently, with a noticeable heterogeneity of cellular responses.

Adhesion of Triple-Negative Breast Cancer Cells under Fluorescent and Soft X-ray Contact Microscopy.

Understanding cancer cell adhesion could help to diminish tumor progression and metastasis. Adhesion mechanisms are currently the main therapeutic target of TNBC-resistant cells. This work shows the distribution and size of adhesive complexes determined with a common fluorescence microscopy technique and soft X-ray contact microscopy (SXCM). The results presented here demonstrate the potential of applying SXCM for imaging cell protrusions with high resolution when the cells are still alive in a physiological buffer. The possibility to observe the internal components of cells at a pristine and hydrated state with nanometer resolution distinguishes SXCM from the other more commonly used techniques for cell imaging. Thus, SXCM can be a promising technique for investigating the adhesion and organization of the actin cytoskeleton in cancer cells.

Homocysteine as a Diagnostic and Etiopathogenic Factor in Children with Autism Spectrum Disorder.

Substantial characteristics of autism are cognitive and psychophysical disorders. Etiopathogenetic factors are thought to be responsible for development of autism in children with genetic predisposition as well as have their effect on the severity of the disorders. The main problem of early identification of patients affected by autism spectrum disorder is that there are no clear diagnostic criteria. The aim of our study was assessment of hair magnesium and serum homocysteine concentrations in children with autism. The presented work is a continuation of previous study in which we investigated the influence of disturbances in magnesium and homocysteine levels in children with autism, performed on a new, larger group of patients. One hundred and forty children had hair magnesium levels analyzed, as well as blood serum levels of homocysteine and magnesium. Hair magnesium analysis was performed using a flame atomic absorption spectrometer, blood serum homocysteine determination was performed using a radioimmunological method, and blood serum magnesium level was determined using a biochemical method. Our research showed normal magnesium blood levels and significantly high homocysteine levels and very low hair magnesium levels. Low concentration of hair magnesium progresses with age. Our hypothesis is that magnesium deficiency, as a relevant epigenetic factor, might be decreasing methylation of homocysteine, therefore decreasing genome transcription and lowering the synaptic plasticity. We suggest that analysis of hair magnesium and serum homocysteine levels might be useful in identification of children with autism spectrum disorder, as well as control of its treatment. Obtained results and performed analysis might therefore justify supplementation of magnesium among children with autism.

Bioelements in hair of children with selected neurological disorders.

We have analyzed concentrations of magnesium (Mg), calcium (Ca), copper (Cu), zinc (Zn) and iron (Fe) in hair of a group of 82 children with mental retardation, in which 9 patients suffered from epilepsy, 18 from the Down's syndrome and 55 from cerebral palsy. Girls comprised little over 50% of the patients. In the group of boys with epilepsy, we found Mg, Ca, Cu and Fe deficiency, and normal level of Zn. In the group of girls with epilepsy, apart from low Fe concentration, a high level of Ca, Mg, Zn, and Cu was noted. For girls with the Down's syndrome, a high or normal level of Ca, Mg, Zn and Cu was found, whereas the Fe concentration varied and presented itself in a non-characteristic way. Both groups of children with cerebral palsy, i.e. boys and girls, displayed low Fe concentration in their hair; low Cu level was found in older patients as well. In this group of patients, we also noted high concentrations of Ca, Mg and Zn in girls and normal in boys. A high concentration of Ca in girls with cerebral palsy requires separate analysis. The obtained results could be useful as guidance in the direction and determination of the amount of possible patient nutritional supplementation.